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Timeline for Kac Moody algebra defintion

Current License: CC BY-SA 3.0

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May 27, 2014 at 20:50 vote accept Sven Cattell
Jan 11, 2014 at 2:38 answer added S. Carnahan timeline score: 4
Sep 6, 2013 at 14:04 comment added Sven Cattell I think you have a good answer to my admittingly soft question.
Sep 5, 2013 at 21:47 comment added S. Carnahan One reason why the extra dimensions are useful is that you end up with a nondegenerate inner product on the weight space. In your first example, your weight space becomes a singular plane embedded in $\mathbb{R}^{2,1}$, and it's harder to see the geometry attached to reflections.
Sep 5, 2013 at 21:44 comment added Sven Cattell I find this dimension in every definition I have read. The Serre relations are all implemented slightly differently, but the dimension of the Cartan subalgebra is always $n+\text{corank}(A)$.
Sep 5, 2013 at 21:41 history edited Sven Cattell CC BY-SA 3.0
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Sep 5, 2013 at 21:22 history edited Jim Humphreys
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Sep 5, 2013 at 21:21 comment added Jim Humphreys Probably part of the problem is that "the" definition doesn't really exist, just a range of closely related definitions. The ideas come from the independent thesis work of Kac and of Moody, but later developments tweaked the notions in various ways. It's a good idea to say more explicitly what version you are looking at.
Sep 5, 2013 at 19:37 history asked Sven Cattell CC BY-SA 3.0